Altman et al. (U.S. Pat. No. 3,792,373) teaches a metal vapor laser in which the room temperature Brewster windows are isolated from the vapor to prevent metal condensation on the windows. The Brewster window is attached to the end of the electrode support tube. At the other end of the electrode support tube is a cathode electrode with a spherical surface. The laser tube is sealed to the electrode support tube by a connecting sleeve assembly with the help of O-rings, pressure limiting rings and threaded collars. The electrode support tube may be removed by disengaging the tube from the correcting sleeve assembly.
Huchital et al. (U.S. Pat. No. 3,745,483) teaches replaceable metal end members having electrodes and Brewster windows. The end members are secured to a glass cylinder through heat resistant gaskets. Hermetic seals are provided by interlocking flanges, overlapping collars, and bolts on the glass and metal members. The problem with most lasers is that the cathode electrode must be welded to the laser end assembly, which makes assembly difficult. Often defects in a weld are not discovered until the laser is filled and operated.
It is an object of the present invention to create a modular cathode assembly for gas lasers in which cathode assembly is simple and does not require welding of parts to the supporting flange.